Today's Question:  What does your personal desk look like?        GIVE A SHOUT

SEARCH KEYWORD -- Start-up

  Configure static IP for Linux

When a Linux server is running, it has to have an IP so that other machines can talk to it. It is often desired that the server would own a static IP so that every time other machines want to connect to it, the same IP address would be used. This is extremely useful when there are virtual machines installed on a host machine where the virtual machine would start and stop now and then.  To configure static IP address for a Linux server, the /etc/network/interfaces needs to be updated. Assumi...

   LINUX,NETWORK,STATIC IP,DNS     2017-07-08 08:39:58

  Examples of bad design

Good designs always help users solve their problems in a convenient and familiar way. It takes little or no time for users getting used to the product with a good design. In contrast, bad designs frequently introduce confusion and complexity to users. Before we design any product, we should think carefully about every aspect of the product. We share some really bad design here to show how they can affect people's life. 1. USB Connector Have you ever put one in right on the first try? We frequen...

   Bad design,Usability,Web design     2013-09-25 22:57:49

  What do programmers like to say usually?

Coding is an very important part of programmer's daily work. But beyond coding, programmers need to do other work as well, they need to fix bugs reported by users, they need to write documents for their codes. Also, they often need to answer questions from customers, bosses and colleagues. What do they often say when they are facing different sort of questions? Today we share some. It's done. I just need to clean up a few things. This is hacky, but I'll fix it soon. This can never happen: It's ...

   Programmer,Execuse,Bug     2013-08-07 07:38:30

  JavaScript tutorial - Creating time delays

There are two ways of creating time delays with JavaScript. The first is more simple and will simply wait for a specified amount of time before executing a function. The second does the same but will repeatedly execute the function. Note, many browsers have a minimum delay length of between 25 and 75 ms, with some of the fastest browsers having a minimum delay of about 3 ms. If a shorter delay is specified, the actual delay will be the minimum delay length. Even with higher numbers, the delay i...

   JavaScript,Time delay,setTimeout,setInterval     2012-04-13 07:17:46

  Why accessing Java HashMap may cause infinite loop in concurrent environment

HashMap in Java is frequently used to handle key/value pairs. But it is not a good candidate to be used in concurrent environment where ConcurrentHashMap should be used instead. If used in concurrent environment, it may cause lots of unexpected behavior even including make the program getting into an infinite loop situation. To understand how this can happen, let's first discuss how HaspMap works internally. In this post we will use implementation of HashMap before Java 8 as example, Java 8 prov...

   JAVA,HASHMAP,INFINITE LOOP     2020-03-29 01:47:00

  Understanding database, instance and schema in Oracle database

Oracle database is the most popular database system among enterprises. To start working on Oracle database, some concepts must be understood first. They include database, instance, schema and user etc. And among these concepts, some have different meanings from those in other database systems such as MS SQL, MySQL, DB2. On the web, there are already some good posts which explain different concepts such as Ask Tom's database vs instances, Difference between database vs user vs schema. In this pos...

   DIFFERENCE,DATABASE,ORACLE DATABASE,INSTANCE,SCHEMA,USER     2016-12-14 23:30:56

  Some tips for writing proper emails

Email is now becoming one necessity of working. We may receive hundreds of emails everyday, they may from our colleagues, friends or clients. We need to exchange ideas, arrange meetings , asking for help etc though email in our work. A proper email can help us achieve what we want to achieve. Here we share some tips for writing a proper email.At the beginning of an email : Thank the reader is a good way to start the email, thank the reader may make the reader feel happy, especially when you ask ...

   EMAIL,TIP,FORMAT,TEMPLATE     2012-07-02 12:26:32

  Additional steps need to implement to setup shadow-boxV2 OPTEE on Raspberry PI

We followed the Shadow-box v2 project from the https://github.com/kkamagui/shadow-box-for-arm to set up the trustZone on Raspberry PI modeB to protect the Linux Kernel. But got a problem when doing the step: [3.6.5. Activate Shadow-Box for ARM and Start Secure Pi!] to create the hash for the memory area. The result is not shown. If you met the same problem, this is what I did to fix the problem on my PI: 1.1  When we do the step [3.5.1. Copy OP-TEE OS with Shadow-Box for ARM and N...

   HARDWARE,RASPBERRY PI     2019-05-20 08:52:55

  Use cases of Java enumeration

JDK 1.5 introduces a new type -- enumeration. In Java, it's just a small feature, but it can bring us much convenience.Here we summarize some use cases of Java enumeration. 1. Constant Prior to JDK 1.5, we can define constant as public static final..., now we can use enumeration to group all constants in one enum variable and it also provides some useful functions. public enum Color {     RED, GREEN, BLANK, YELLOW   }  2.In Swit...

   Java, Enum,enumeration     2013-01-05 09:15:30

  Build Hadoop environment in Linux

Hadoop standalone installation: 1. Install JDK Install JDK with below command: sudo apt-get install sun-java6-jdk Configure Java environment, open /etc/profile, add below contents: export JAVA_HOME = （Java installation directory） export CLASSPATH =".:$JAVA_HOME/lib:$CLASSPATH" export PATH = "$JAVA_HOME/:PATH" Verify installation of Java Type java --version, if it outputs Java version information, then Java is successfully installed. 2. Install SSH Install SSH with below command: sudo ...

   Hadoop.Linux,Configuration     2013-07-31 23:22:27

RECENT